Ventilator

Abstract

A ventilator intended to be connected to a patient for breathing therapy has a control unit having an input for receiving EMG signals from an EMG detector and an output for an EMG based control signal and a pneumatic unit for generating breathing gas flows dependent on the EMG based control signal is described. The ventilator has a detector for determining a parameter related to breathing dynamics for the patient, this detector being connected to the control unit and control unit controlling the pneumatic unit dependent on the parameter related to breathing dynamics in the case of loss of EMG signals at the input.

Description

BACKGROUND OF THE INVENTION[0001]1. Field of the Invention[0002]The present invention relates to a control unit for a ventilator controlled in response to respiratory bioelectric signal in particular the sensed diaphragmal electromyographic (EMG) activity (EAdi). It also relates to a method of controlling a ventilator controlled by a respiratory bioelectric signal.[0003]2. Description of the Prior Art[0004]Ventilators of the above type typically are used to support patients having insufficient breathing capacity in a hospital environment such as an intensive care unit or for simpler applications such as home care, but could also be used as an integral part of an anaesthesia machine.[0005]A breathing effort is controlled by the breathing centre in the brain, the main breathing muscle, the diaphragm, is activated through nerve transmission in the phrenic nerve. When the muscle is activated, it contracts and lowers the pressure in the thorax and thus creates an inspiratory flow.[0006]E...

AI Technical Summary

Benefits of technology

[0013]It is an object of the present invention to provide a ventilator controlled by respiratory bioelectric signals, such as EMG, that will function satisfactorily if the bioelectric signals signal is lost.

[0028]The present invention provides a safeguard for the situation, that the bioelectric signal, which allows a breathing therapy directly following the need of the patient, is no longer sensed. The present invention also handles a more complex situation where the apparatus needs to distinguish between the causes of signal loss, which can be due to hardware / transmission related errors or changes in sedation or the pathological condition of a patient, in order to provide the best therapy under the prevailing circumstances.

[0029]The present invention also gives the physician a possibility to correct hardware faults, catheter placement and medication / sedation without exposing the patient to any hazards due to unexpected interruptions in the ventilator support.

Problems solved by technology

A problem that may occur when controlling in dependence of EMG signals is that the signal may cease, slowly or abruptly.

This can be caused by problems in capturing the signals, but can also occur because the patient does no longer generate a neurological breathing signal from the breathing centre.

An abrupt loss of signal could be due to that the catheter is dislocated or disconnected by accident, such as if the patient moves in an uncontrolled way, or in a controlled way by the ventilator operator.

Another problem that may occur in EMG controlled ventilation is that the internal regulatory monitoring of inspiration and expiration phases in the ventilator is made difficult because the EMG controlled ventilator does not have the normal time based differentiation between these phases.

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